The long-term goal of this research is to explore the effects of age on the physiological processes underlying auditory perception. The specific aims of this study are to examine the relative contribution of peripheral and central auditory processes to one aspect of auditory perception, temporal (timing) resolution. Temporal resolution is an auditory perceptual skill that deteriorates with age and/or hearing loss, is thought to be important for the understanding of degraded speech, and has shown promise for remediation. Results of behavioral studies provide conflicting evidence regarding the auditory processes underlying temporal deficits (i.e., diminished ability to follow rapid acoustic changes over time). Peripherally, loss of active cochlear processes is thought to impair the perception of temporal cues. This hypothesis is supported by behavioral findings of poor temporal resolution among older listeners with hearing loss. Poor temporal resolution is also attributed to the slowing of central auditory processes inherent in biological aging. Support for this hypothesis is provided by behavioral studies showing poor temporal resolution by most older listeners, regardless of hearing status. Recent research has shown, however, that some older adults with apparent cochlear damage (i.e., sensorineural hearing loss) exhibit normal temporal resolution. The relative contribution of peripheral and central processes to individual temporal deficits is unclear as peripheral auditory function is often only grossly assessed and behavioral studies are heavily influenced by attention, motivation, task, etc. In the proposed studies, the functional status of two distinct regions of the auditory system (one peripheral and one central) will be directly assessed using two physiological audiometric techniques: distortion product otoacoustic emissions (DPOAEs) and auditory evoked potentials (AEPs). Age and hearing-loss related changes have been documented using both techniques, but the contribution of those changes to deficits of temporal resolution is not known. Once the processes that underlie behavioral temporal deficits are described, diagnostic and remediation strategies may be designed to identify/target specific areas of weakness in individual older adults.